java uses Base64 to realize file encryption and decryption

This article example for everyone to share Java implementation of Base64 to file encryption, decryption of the specific code, for your reference, the specific content is as follows

package test.base64;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
/**
*  Pass pictures between servers 
*/
public class TestCase {
 
public static void main(String[] args) {
//  Converts a picture file into a byte array string, and performs the Base64 Coding processing 
String strImg = GetImageStr();
System.out.println(strImg);
//  On a byte array string Base64 Decode and generate pictures 
GenerateImage(strImg);
}
public static String GetImageStr() {
String imgFile = "d:\\java.pdf";//  Pictures to be processed 
InputStream in = null;
byte[] data = null;
//  Read the picture byte array 
try {
in = new FileInputStream(imgFile);
data = new byte[in.available()];
in.read(data);
in.close();
} catch (IOException e) {
e.printStackTrace();
}
//  Byte array Base64 Code 
BASE64Encoder encoder = new BASE64Encoder();
return encoder.encode(data);//  Return Base64 Encoded byte array string 
}
public static boolean GenerateImage(String imgStr) {
if (imgStr == null){ //  Image data is empty 
return false;
}
BASE64Decoder decoder = new BASE64Decoder();
try {
// Base64 Decoding 
byte[] b = decoder.decodeBuffer(imgStr);
for (int i = 0; i < b.length; ++i) {
if (b[i] < 0) {//  Adjust exception data 
b[i] += 256;
}
}
//  Generate jpg Picture 
String imgFilePath = "d:\\new.pdf"; //  Newly generated picture 
OutputStream out = new FileOutputStream(imgFilePath);
out.write(b);
out.flush();
out.close();
return true;
} catch (Exception e) {
return false;
}
}
}

This site also shares 1 segment of java code to realize base64 encryption and decryption of files

Base64 encoding method: Every 3 bytes of 8bit are converted into 4 bytes of 6bit, in which every 6 valid Bbit of the 4 bytes after conversion are valid data, and the remaining 2 bytes are supplemented with 0 to become 1 byte. java can directly call the algorithm for base64 encryption and decryption.

public class base64 {

  public static void main(String[] args){
    File file = new File("D:\\base64.txt");
    String result = getFromBase64(file2String(file));
    System.out.println(result);
  }

  // File to string 
  public static String file2String(File file){
    try {
      BufferedReader buffer = new BufferedReader(new FileReader(file));
      StringBuilder sb = new StringBuilder();
      String temp;
      while((temp = buffer.readLine()) !=null ){
        sb.append(temp);

      }
      return sb.toString();
    } catch (FileNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
      return null;
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
      return null;
    }
  }
  // Encryption 
  public static String getBase64(String str){
    byte[] b = null;
    String s = null;
    try {
      b = str.getBytes("utf-8");
    } catch (UnsupportedEncodingException e) {
      e.printStackTrace();
    }
    if( b != null){
       s = new BASE64Encoder().encode(b);
    }
    return s;

  }

  // Decryption 
  public static String getFromBase64(String str){
    byte[] b = null;
    String result = null;
    if(str != null){
       BASE64Decoder decoder = new BASE64Decoder(); 
       try { 
          b = decoder.decodeBuffer(str); 
          result = new String(b, "utf-8"); 
        } catch (Exception e) { 
          e.printStackTrace(); 
        } 
    }
    return result;
  }

}